Electronic apparatus, presence communication system, and computer-readable recording medium

ABSTRACT

An electronic apparatus comprises a plurality of communication units including a first communication unit which communicates via a first communication network and a second communication unit which communicates via a second communication network. The electronic apparatus acquires presence information indicating a communication state of a communication apparatus from a presence server managing a communication state of a communication apparatus on a communication network, via at least one communication network. The electronic apparatus acquires presence information of an alternative communication apparatus being as a communication apparatus which communicates via the second communication network in place of the second communication unit included in itself. The electronic apparatus determines as to whether the alternate communication apparatus is in an online state, based on the acquired presence information. The electronic apparatus suppresses electric power to be consumed by the second communication unit, when the alternate communication apparatus is in an online state.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic apparatus comprising aplurality of communication units.

2. Description of the Related Art

Unexamined Japanese Patent Application KOKAI Publication No. 2002-199426discloses a mobile terminal which is communicable via a plurality ofcommunication systems.

Specifically, the mobile terminal is provided with a plurality ofwireless communication units which are communicable via a plurality ofcommunication systems. Depending on communication quality given for eachof the communication systems, the mobile terminal switches acommunication system for the use.

The above-mentioned mobile terminal is provided with a plurality ofwireless communication units, all of which are supplied with electricpower on a steady basis. Being compared with a mobile terminal includingonly one wireless communication unit, therefore, the mobile terminal isprovided with increased consumption electric power.

An electronic apparatus, such as a mobile terminal, employs a battery asa power source which supplies electric power for use in an operation inmany cases. In case of such an electronic apparatus, thus, operable timeis significantly reduced by the battery.

SUMMARY OF THE INVENTION

The present invention has been made, in consideration of theabove-mentioned situation. The object of the present invention is, incase of an electronic apparatus having a plurality of communicationunits, to provide an electronic apparatus or the like which can suppresselectric power consumption.

In order to achieve the above-mentioned object, an electronic apparatusaccording to a first aspect of the present invention relates to anelectronic apparatus which communicates via a plurality of communicationnetworks including a first communication network and a secondcommunication network being different from the first communicationnetwork, and comprises:

a plurality of communication units including a first communication unitwhich communicates via the first communication network and a secondcommunication unit which communicates via the second communicationnetwork;

a presence information acquiring unit which acquires presenceinformation indicating a communication state of an alternatecommunication apparatus being as a communication apparatus whichcommunicates via the second communication network in place of the secondcommunication unit;

an online determining unit which determines as to whether the alternatecommunication apparatus is in an online state, based on the presenceinformation acquired by the presence information acquiring unit; and

a consumed electric power controlling unit which suppresses electricpower to be consumed by the second communication unit, when the onlinedetermining unit determines that the alternate communication apparatusis in an online state.

Furthermore, a presence communication system according to a secondaspect of the present invention comprises:

a presence server which manages a communication state of a communicationapparatus; and

an electronic apparatus which communicates via a plurality ofcommunication networks including a first communication network and asecond communication network being different from the firstcommunication network, wherein

the presence server transmits presence information indicating acommunication state of an alternate communication apparatus being as acommunication apparatus which communicates via the second communicationnetwork in place of the second communication unit, to the electronicapparatus, and

the electronic apparatus further comprises:

a plurality of communication units including a first communication unitwhich communicates via the first communication network and a secondcommunication unit which communicates via the second communicationnetwork;

a presence information acquiring unit which acquires presenceinformation of the alternate communication apparatus transmitted by thepresence server, via at least one of a plurality of the communicationnetworks;

an online determining unit which determines as to whether the alternatecommunication apparatus is in an online state, based on the presenceinformation acquired by the presence information acquiring unit; and

a consumed electric power controlling unit which suppresses electricpower to be consumed by the second communication unit, when the onlinedetermining unit determines that the alternate communication apparatusis in an online state.

Furthermore, a computer-readable recording medium according to a thirdaspect of the present invention stores a program which causes acomputer, comprising a plurality of communication units including afirst communication unit which communicates via a first communicationnetwork and a second communication unit which communicates via a secondcommunication network being different from the first communicationnetwork and, communicating via a plurality of communication networksincluding the first communication network and the second communicationnetwork, to execute:

a present presence information acquiring step of acquiring presenceinformation indicating a communication state of an alternatecommunication apparatus being as a communication apparatus whichcommunicates via the second communication network in place of the secondcommunication unit;

an online determining step of determining as to whether the alternatecommunication apparatus is in an online state, based on the presenceinformation acquired in the presence information acquiring step; and

a consumed electric power controlling step which suppresses electricpower to be consumed by the second communication unit, when it isdetermined that the alternate communication apparatus is in an onlinestate in the online determining step.

According to the present invention, electric power consumption can besuppressed by an electronic apparatus including a plurality ofcommunication units.

BRIEF DESCRIPTION OF THE DRAWINGS

These objects and other objects and advantages of the present inventionwill become more apparent upon reading of the following detaileddescription and the accompanying drawings in which:

FIG. 1 represents a block diagram illustrating the whole configurationof a presence communication system according to embodiment 1 of thepresent invention;

FIG. 2 represents a block diagram illustrating a circuit configurationof a mobile communication terminal according to embodiment 1 of thepresent invention;

FIG. 3A represents a diagram indicating presence information, FIG. 3Brepresents a diagram indicating presence monitoring target information,and FIG. 3C represents a diagram indicating forwarding information;

FIGS. 4A, 4B, and 4C represent flowcharts indicating an operationrelated to each element constituting a presence communication system,when a mobile communication terminal turns a second wirelesscommunication unit from an on-state into an off-state, in embodiment 1of the present invention;

FIGS. 5A, 5B, and 5C represent a flowchart indicating an operationrelated to each element constituting a presence communication system,when a mobile communication terminal turns a second wirelesscommunication unit from an off-state into an on-state, in embodiment 1of the present invention;

FIG. 6 represents a flowchart indicating a detailed operation related toa mobile communication terminal when controlling power supply into awireless communication unit in embodiment 1 of the present invention;

FIG. 7 represents a block diagram illustrating a circuit configurationof a mobile communication terminal according to embodiment 2 of thepresent invention; and

FIG. 8 represents a flowchart indicating a detailed operation related toa mobile communication terminal when controlling a discontinuousreception cycle in embodiment 2 of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1

Hereinafter, embodiment 1 of the present invention is explained withreference to diagrams.

Embodiment 1 employs a mobile communication terminal 1 and a mobilecommunication terminal 2, each of which being as a communicationapparatus, as an electronic apparatus.

First of all, the whole configuration of a presence communication systemPS according to embodiment 1 is explained with reference to FIG. 1.

The presence communication system PS comprises a mobile communicationterminal 1, a mobile communication terminal 2, a first wirelesscommunication system 3, a second wireless communication system 4, a callmanager server 5, a location registration server 6, a presence server 7,a number comparing DB (Database) server 8, and a network N. The firstwireless communication system 3 includes a first base station 3 a and apresence information notifying apparatus 3 b. The second wirelesscommunication system 4 includes a second base station 4 a.

The mobile communication terminal 1, the mobile communication terminal2, the first base station 3 a, the presence information notifyingapparatus 3 b, the second base station 4 a, the call manager server 5,the location registration server 6, the presence server 7, the numbercomparing DB server 8 reciprocally transmit data via the network N.

The mobile communication terminal 1, which is provided with a pluralityof wireless communication units, represents an electronic apparatusaccording to embodiment 1. The mobile communication terminal 1 receivesaudio (voice) signals or data signals via the first wirelesscommunication system 3 and the second wireless communication system 4,with the use of a plurality of the wireless communication units.Furthermore, the mobile communication terminal 1 is communicable inaccordance with an SIP (Session Initiation Protocol).

The details concerning the circuit configuration of the mobilecommunication terminal 1 are to be hereinafter described.

The mobile communication terminal 2 represents an electronic apparatusbeing provided with one wireless communication unit, which is not shownin the figure. The mobile communication terminal 2 receives audiosignals or data signals via the second wireless communication system 4,with the wireless communication unit. Further, the mobile communicationterminal 2 is communicable in accordance with an SIP. Furthermore, themobile communication terminal 1 and the mobile communication terminal 2share the same owner.

The first wireless communication system 3 represents a wide-areawireless communication network, which includes the first base station 3a and the presence information notifying apparatus 3 b. The firstwireless communication system 3, for example, represents a portablecommunication system with the use of a cellular method, such as a CDMA(Code Division Multiple Access).

The first base station 3 a relays communication among a plurality ofelectronic apparatuses, which is via the first wireless communicationsystem 3.

The presence information notifying apparatus 3 b notifies presenceinformation transmitted from a presence server 7, which is to behereinafter described, to the mobile communication terminal 1, while themobile communication terminal 1 communicating via the first wirelesscommunication system 3 is in a discontinuous idle state which indicatesthat a traffic channel is disconnected in an idle state.

The second wireless communication system 4 represents a local wirelesscommunication network, which is provided with the second base station 4a. The second wireless communication system 4, for example, represents awireless LAN (Local Area Network) communication system, such as an IEEE(the Institute of Electrical and Electronic Engineers) 802.11b standard.

The second base station 4 a relays communication among a plurality ofelectronic apparatuses, which is via the second wireless communicationsystem 4.

The call manager server 5 represents a server for use of a call managerwhich processes a message generated in accordance with an SIP.

The location registration server 6 stores information which relates anapparatus identifier such as a phone number being imparted to anelectronic apparatus, to location information such as an IP address.

The presence server 7 represents a server apparatus which manages anoperational state (including a communication state) of an electronicapparatus on a communication network. The presence server 7 storespresence information indicating the operational state for eachelectronic apparatus, and transmits presence information concerningother electronic apparatuses, to an electronic apparatus whichcommunicates with the use of a presence communication system PS.Furthermore, an electronic apparatus on a communication network withinthe presence communication system PS transmits presence informationindicating a post-variation operational state, when an operational stateof a wireless communication unit included in itself is varied, to thepresence server 7.

Here, presence information specifically represents informationindicating a communication state found in a wireless communication unitof an electronic apparatus for use of communication by a phone, anelectronic mail, or the like, and a user state of the electronicapparatus. Presence information represents, for example, “on line” whichindicates an electronic apparatus being with a communicable state,“connect state” which indicates an electronic apparatus being with acommunicating state, “online (getting out of the seat)” which indicatesan electronic apparatus being with a communicable state, but a usergetting out of the seat, “offline” which indicates an electronicapparatus being with a incommunicable state, and others.

As being illustrated in FIG. 3A, presence information relates anapparatus identifier AI specifying an electronic apparatus (a phonenumber, an IP address, a unique title being imparted by a user with adetermination for each electronic apparatus, and others), a presence PRindicating a communication state found in a wireless communication unitof an electronic apparatus and a user state of the electronic apparatus,a user identifier UI indicating a user of an electronic apparatus(owner), to one another.

The number comparing DB server 8 stores forwarding information forforwarding a reception into any electronic apparatus to other electronicapparatuses. The number comparing DB server 8 is compared by a callmanager server 5, when a reception is forwarded.

At this point, as being illustrated in FIG. 3C, the forwardinginformation represents information reciprocally relating a forwardingsource electronic apparatus to a forwarding destination electronicapparatus among a plurality of electronic apparatuses owned by a user,by an apparatus identifier being imparted at each electronic apparatus.When a reception into the second wireless communication unit 132provided at the mobile communication terminal 1 is intended to beforwarded to the mobile communication terminal 2 owned by a user, by wayof example, a user of the mobile communication terminal 1 registers“mobile communication terminal 1_second wireless communication unit 132”as a forwarding source in the number comparing DB server 8 and “mobilecommunication terminal 2” as a forwarding destination, by relating toone another. In case of such forwarding information being stored in thenumber comparing DB server 8, the mobile communication terminal 2 beingas a forwarding destination receives in place of the second wirelesscommunication unit 132 provided at the mobile communication terminal 1being as a forwarding source and communicates with an electronicapparatus being as a transmitter, when any electronic apparatusestransmit to the second wireless communication unit 132 provided at themobile communication terminal 1.

Next, the mobile communication terminal 1 according to embodiment 1 isto be explained.

As being illustrated in FIG. 2, the mobile communication terminal 1 isprovided with a controlling unit 11, a storing unit 12, a communicationunit 13, a common circuit unit 14, a power source unit 15, an operationunit 16, a display unit 17, an audio microphone 18, an audio speaker 19,and a bus 10.

The controlling unit 11 is provided with a CPU (Central Processing Unit)and controls an operation as a whole given by the mobile communicationterminal 1, in accordance with an operation program stored in thestoring unit 12.

Furthermore, the controlling unit 11 is provided with a communicationcontrolling unit 111 and an electric power supply controlling unit 112.

The communication controlling unit 111 controls the wirelesscommunication units, by giving an instruction to change an operationstate concerning a communication function to a first wirelesscommunication unit 131 and a second wireless communication unit 132 bothof which provided at the communication unit 13. The communicationcontrolling unit 111 controls the first wireless communication unit 131and the second wireless communication unit 132 both of which as being anoperation state such as a transmission, a reception, a reception queuing(idle state) of a wireless signal and others, by way of example.

Furthermore, a time slot TS is defined in an awaiting wireless signal.Information to be received is also included for each time cycle adoptedfor the time slot TS.

The communication controlling unit 111 supplies electric power into thefirst wireless communication unit 131 and into the second wirelesscommunication unit 132 for reducing electric power consumption of abattery 15 b provided at the power source unit 15 by coupling with atiming given by the time slot TS, but terminates power supply at othertimings.

The electric power supply controlling unit 112 receives presenceinformation concerning all the electronic apparatuses to be used by auser from the communication controlling unit 111 and controls anoperation state concerning the power source unit 15 in response to thepresence information.

Furthermore, the electric power supply controlling unit 112 is providedwith a presence information acquisition controlling unit 112 a, apresence specifying unit 112 b, an electric power supply determiningunit 112 c, and a forwarding control unit 112 d. The details concerningeach constituent element provided at the electric power supplycontrolling unit 112 are to be hereinafter described.

The storing unit 12 is comprised of a nonvolatile memory such as a flashmemory and an RAM (Random Access Memory) and stores a program and othersfor causing the controlling unit 11 to execute a process as beingindicated in the flowcharts given in FIGS. 4A to 4C, FIGS. 5A to 5C, andFIG. 6. Furthermore, the storing unit 12 functions as a working memoryprovided for the controlling unit 11.

Furthermore, the storing unit 12 is provided with a presence informationstorage region 121, a presence monitoring target information storageregion 122, an electric power supply state storage region 123, acommunication state storage region 124, a forwarding information storageregion 125, and a discontinuous reception cycle storage region 126.

The presence information storage region 121 stores presence informationreceived from the presence server 7, as being indicated in FIG. 3A.

Among presence information, an apparatus identifier AI for specifying anelectronic apparatus registers the first wireless communication unit 131and the second wireless communication unit 132 both of which areprovided at the mobile communication terminal 1. In this way, in case ofone electronic apparatus having a plurality of communication units, anapparatus identifier AI is assigned for each communication unit.

Furthermore, a presence PR given by an electronic apparatus includes“online,” “offline,” and “connect state” and is established byinformation combining an electric power supply state and a communicationstate both of which concerning an electronic apparatus. Furthermore, auser identifier UI identifies “Mr. Taro TSUSHIN” as an owner of themobile communication terminal 1.

The presence monitoring target information storage region 122 storespresence monitoring target information as being illustrated in FIG. 3B.The presence monitoring target information represents a list concerningelectronic apparatuses which can be intended for monitoring presenceinformation and also represents information input by a user from anoperation unit 16. Among electronic apparatuses owned by a user, anelectronic apparatus (alternate electronic apparatus) which arecommunicable via the second wireless communication system 4 in place ofthe second wireless communication unit 132 is specifically registered topresence monitoring target information as a monitoring target (targetfor monitoring).

As being illustrated in FIG. 3B, presence monitoring target informationrepresents information relating an apparatus identifier AI indicating anelectronic apparatus being as a target for monitoring presence, to auser identifier UI indicating an owner of an electronic apparatus. InFIG. 3B, for example, the mobile communication terminal 2, a PDA(Personal Digital Assistants) and others are registered. However, a useridentifier UI needs not to necessarily be registered. Furthermore, FIG.1 illustrates the mobile communication terminal 2 as an examplerepresenting an electronic apparatus intended for monitoring. However,an electronic apparatus intended for monitoring simply needs to be anelectronic apparatus which is communicable via the second wirelesscommunication system 4 as being listed in FIG. 3B, and may register onepart as well as a plurality of parts.

When the mobile communication terminal 1 receives presence informationfrom the presence server 7, the presence monitoring target informationis compared by the presence specifying unit 112 b for determining as towhether an electronic apparatus having the received presence informationis a target for monitoring.

The electric power supply state storage region 123 stores electric powersupply information indicating an electric power supply state of aplurality of wireless communication units provided at the communicationunit 13.

The electric power supply state represents “online” when electric poweris supplied into a wireless communication unit provided at thecommunication unit 13, but represents “offline” when electric power isnot supplied into a wireless communication unit provided at thecommunication unit 13.

The communication state storage region 124 receives and storescommunication state information indicating an operation state concerninga communication function caused by a plurality of wireless communicationunits provided at the communication unit 13, from the communicationcontrolling unit 111.

Communication state information, for example, represents “idle state(standby state)”, “connect state (communicating state)”, “access state”,“wireless communication unit switching state”, and others.

A presence PR indicating an operation state found in the mobilecommunication terminal 1 is comprised of combining electric power supplyinformation and communication state information. Furthermore, a presencePR such as “online (forwarding data included)” may be provided. In caseof providing such a presence PR, a user can easily grasp as to whetherforwarding data is included at an electronic apparatus provided as aforwarding destination for data.

The forwarding information storage region 125 stores informationconcerning a forwarding destination which relates a receiving electronicapparatus to an electronic apparatus being a forwarding destination forthe reception.

As being illustrated in FIG. 3C, information concerning a forwardingdestination relates an apparatus identifier AI indicating a receivingelectronic apparatus to a forwarding destination identifier TIindicating an electronic apparatus being as a forwarding destination forthe reception.

Furthermore, information concerning a forwarding destination ischangeable by an input from the operation unit 16 by a user.

An forwarding destination identifier TI includes a first forwardingdestination identifier TI 1 which indicates a first forwardingdestination to which a reception of a voice signal is forwarded and asecond forwarding destination identifier TI 2 which indicates a secondforwarding destination to which a reception of a data signal isforwarded.

In this way, in case of an example shown in FIG. 3C illustratinginformation concerning a forwarding destination, a voice signal beingtransmitted to a notebook PC for use in a company is received by thenotebook PC as it is, and a data signal being transmitted to thenotebook PC is forwarded to a PC found at home for a user.

The discontinuous reception cycle storage region 126 stores a“discontinuous reception cycle” which indicates a timing that thebattery 15 b supplies electric power into the first wirelesscommunication unit 131 and into the second wireless communication unit132 in an idle state, in order to cause a communication functionprovided at the first wireless communication unit 131 and at the secondwireless communication unit 132 to enter in the idle state.

The discontinuous reception cycle storage region 126 found in embodiment1 stores a predetermined discontinuous reception cycle T1. Thediscontinuous reception cycle T1 is compared while the first wirelesscommunication unit 131 and the second wireless communication unit 132are normally awaiting reception in an idle state. Thus, a T1 ishereinafter referred to as a “normal discontinuous reception cycle.”

The communication unit 13 is provided with the first wirelesscommunication unit 131 and the second wireless communication unit 132.

The first wireless communication unit 131 represents a wide-areawireless communication unit which communicates via the first wirelesscommunication system 3. The second wireless communication unit 132represents a local wireless communication unit which communicates viathe second wireless communication system 4. Furthermore, a wirelesscommunication unit provided at the mobile communication terminal 2represents a local wireless communication unit which communicates viathe second wireless communication system 4, as in the second wirelesscommunication unit 132.

The first wireless communication unit 131 communicates with the firstbase station 3 a via an antenna 131 a, and transmits/receives an audiosignal, a video signal and a data signal. For example, the firstwireless communication unit 131 receives, demodulates, and outputs asignal defining presence information, from the presence server 7.

The second wireless communication unit 132 communicates with the secondbase station 4 a via an antenna 132 a, and transmits/receives an audiosignal, a video signal and a data signal. For example, the secondwireless communication unit 132 receives, demodulates, and outputs asignal defining presence information, from the presence server 7.

The mobile communication terminal 1 is communicable with otherelectronic apparatuses via the first wireless communication system 3being as a wide-area wireless communication system, with the use of thefirst wireless communication unit 131. Furthermore, the mobilecommunication terminal 1 is communicable with other electronicapparatuses via the second wireless communication system 4 being as alocal wireless communication system, with the use of the second wirelesscommunication unit 132.

This allows the mobile communication terminal 1 to include wide-areaconnectibility characterizing a wide-area wireless communication systemas well as inexpensive and high-speed data communicabilitycharacterizing a local wireless communication system.

Furthermore, the common circuit unit 14 represents a circuit whichperforms a process to a wireless signal, which is common to the firstwireless communication unit 131 and the second wireless communicationunit 132.

The power source unit 15 is provided with a power source controller 15 aand a battery 15 b.

The power source controller 15 a supplies electric power for use of anoperation into the first wireless communication unit 131 and into thesecond wireless communication unit 132, in accordance with a controlinstruction given by the electric power supply controlling unit 112.

Furthermore, the power source controller 15 a supplies electric powerinto each constituent element within the mobile communication terminal 1in accordance with an instruction given by the electric power supplycontrolling unit 112, when the power of the mobile communicationterminal 1 is in an “ON” state, but supplies electric power for use ofawaiting power ON operation into the controlling unit 11 and into theoperation unit 16, when the power is in an “OFF” state.

The operation unit 16 is provided with various keys and buttons all ofwhich are for use in inputting an instruction and data by a user. Thevarious instructions and data are input the operation unit 16 and sentto the controlling unit 11. Furthermore, the operation unit 16 isprovided with power button which turn the power of the mobilecommunication terminal 1 to an “ON” state or to an “OFF” state.

A user may, for example, give input when imparting a unique title to anelectronic apparatus, and give an instruction concerning turning thepower of the mobile communication terminal 1 to an “ON” state or to an“OFF” state, or the like, by operating the operation unit 16.

The display unit 17 is comprised of an LCD (Liquid Crystal Display)panel with a dot matrix type and a driver circuit, and displays anyimages.

The audio microphone 18 collects audio signals while calling or thelike, to be supplied into the communication unit 13.

The audio speaker 19 outputs demodulated audio signals while calling orthe like.

The bus 10 reciprocally transmits data among the controlling unit 11,the storing unit 12, and the display unit 17.

Next, the details concerning each constituent element provided at theelectric power supply controlling unit 112 are to be explained.

The presence information acquisition controlling unit 112 a acquirespresence information received from the presence server 7 by thecommunication unit 13, which is indicated in FIG. 3A, and causes thepresence information storage region 121 to store. This allows a user toconfirm a communication state found in a wireless communication unitprovided at an electronic apparatus on a communication network within apresence communication system PS, when the presence information isvisualized. Furthermore, the mobile communication terminal 1 may receiveonly presence information found in an electronic apparatus in which apresence PR is modified by the presence server 7. In such a case, thepresence information acquisition controlling unit 112 a needs to rewritea modified portion only within the presence information which ispreviously stored in the presence information storage region 121, basedon the received presence information.

Furthermore, the presence information acquisition controlling unit 112 anotifies the presence specifying unit 112 b that presence information isreceived, when the presence information is received.

The presence specifying unit 112 b determines as to whether anelectronic apparatus indicating the communication state by the presenceinformation represents an electronic apparatus as a monitoring target,with reference to presence information stored in the presenceinformation storage region 121 which is found in FIG. 3A, with presencemonitoring target information stored in the presence monitoring targetinformation storage region 122 which is found in FIG. 3B.

The electric power supply determining unit 112 c determines as towhether electric power supply into the first wireless communication unit131 or into the second wireless communication unit 132 is to becontinued or to be terminated, based on the presence PR concerning anelectronic apparatus which is determined as being a monitoring target bythe presence specifying unit 112 b, on electric power supply informationconcerning the communication unit 13 stored in the electric power supplystate storage region 123, and on communication state informationconcerning the communication unit 13 stored in the communication statestorage region 124.

Furthermore, the electric power supply determining unit 112 c instructsthe power source controller 15 a to control electric power supply intothe first wireless communication unit 131 and into the second wirelesscommunication unit 132 both of which are from the battery 15 b, inaccordance with the determined result.

The forwarding controlling unit 112 d requests the call manager server 5to forward a reception into the mobile communication terminal 1 to otherelectronic apparatuses, in accordance with forwarding information.

Next, with reference to the flowcharts found in FIGS. 4A to 4C, thedetails concerning an operation of each constituent element provided atthe presence communication system PS, when the mobile communicationterminal 1 controls the state of the second wireless communication unit132 from “ON” to “OFF” in order to suppress electric power consumptionof the battery 15 b, are to be explained.

Furthermore, that both the first wireless communication unit 131 and thesecond wireless communication unit 132 are supplied with electric powerand are activated with an online state when the power of the mobilecommunication terminal 1 is turned into an “ON” state, is assumed.

The processes illustrated in flowcharts found in FIGS. 4A to 4C areinitiated, when a user performs a power ON operation provided for themobile communication terminal 1, by pressing a power button provided atthe mobile communication terminal 1. Furthermore, an explanation mainlyconcerning an operation related to the second wireless communicationunit 132 among operations provided for the mobile communication terminal1 is to be given in FIGS. 4A to 4C.

When a user performs a power ON operation (step A10 found in FIG. 4A),the electric power supply controlling unit 112 supplies electric powerfor use in an operation into the second wireless communication unit 132(step A11). Furthermore, the electric power supply controlling unit 112supplies electric power for use in an operation into the first wirelesscommunication unit 131 in a similar manner.

The second wireless communication unit 132 transmits a request toestablish a session to the call manager server 5 via the second basestation 4 a (step A12). The call manager server 5 receives the requestto establish a session (step A50) and executes a process to establish asession (step A51). This allows a session to be established in betweenthe second wireless communication unit 132 and the call manager server 5(step A13).

Furthermore, the second wireless communication unit 132 requests thelocation registration server 6 to register location information via thecall manager server 5, when a request to establish a session istransmitted. As a result of this process, the call manager server 5requests the location registration server 6 to register locationinformation concerning the second wireless communication unit 132provided at the mobile communication terminal 1 (step A52). The locationregistration server 6 receives a request to register locationinformation (step A60) and executes a process to register locationinformation (step A61).

Furthermore, the second wireless communication unit 132 requests thepresence server 7 to register presence information via the call managerserver 5, when a request to establish a session is transmitted. As aresult of this process, the call manager server 5 requests the presenceserver 7 to register presence information concerning the second wirelesscommunication unit 132 provided at the mobile communication terminal 1(step A53).

The presence server 7 receives a request to register presenceinformation (step A70) and executes a process to register presenceinformation (step A71). The presence server 7 recognizes that the secondwireless communication unit 132 provided at the mobile communicationterminal 1 is in an online (valid) state, by a request from the callmanager server 5 in step A53.

The second wireless communication unit 132 requests to register locationinformation and presence information, and subsequently awaits areception of a wireless signal from other electronic apparatuses (stepA14). As in the second wireless communication unit 133, the firstwireless communication unit 131 also establishes a session with the callmanager server 5. Location information and presence information, both ofwhich concerning the first wireless communication unit 131, aresubsequently registered in the location registration server 6 and in thepresence server 7.

Once the second wireless communication unit 132 is transited into anidle state, that a user has performed a power ON operation provided forthe mobile communication terminal 2 is assumed. With a power ONoperation performed by a user (step A20 found in FIG. 4B), a wirelesscommunication unit provided at the mobile communication terminal 2 issupplied with electric power for use in an operation.

At the moment, the mobile communication terminal 2 (wirelesscommunication unit provided at the mobile communication terminal 2)transmits a request to establish a session to the call manager server 5via the second base station 4 a (step A21). The call manager server 5receives a request to establish a session (step A54), and executes aprocess to establish a session (step A55). This allows a session to beestablished in between the mobile communication terminal 2 and the callmanager server 5 (step A22).

Furthermore, the mobile communication terminal 2 requests the locationregistration server 6 to register location information via the callmanager server 5 when a request to establish a session is transmitted,and requests the presence server 7 to register presence information. Inorder to perform this process, the call manager server 5 requests thelocation registration server 6 to register location informationconcerning the mobile communication terminal 2 (step A56), and requeststhe presence server 7 to register presence information concerning themobile communication terminal 2 (step A57). With a request from the callmanager server 5 found in step A57, the presence server 7 recognizesthat a wireless communication unit provided at the mobile communicationterminal 2 is in an online (valid) state.

Once a session is established, the mobile communication terminal 2 istransited into an idle state (step A23), and awaits until the subsequentprocess is requested.

The location registration server 6 receives a request to registerlocation information (step A62), and executes a process to register thelocation information (step A63).

The presence server 7 receives a request to register presenceinformation (step A72), and executes a process to register the presenceinformation (step A73).

The presence server 7 notifies the mobile communication terminal 1 ofregistered presence information of the mobile communication terminal 2,which is presence information indicating that the mobile communicationterminal 2 is transited into an online state, via the second wirelesscommunication system 4 (step A74 found in FIG. 4C).

Here, the presence server 7 notifies the mobile communication terminal 1of presence information via the “second wireless communication system 4”because of recognition that the second wireless communication unit 132,which communicates via the second wireless communication system 4, is inan online (valid) state by a process found in step A53. Further, in caseof recognition that the first wireless communication unit 131 is in anonline (valid) state, the presence server 7 may notify the mobilecommunication terminal 1 of the presence information via the firstwireless communication system 3.

The second wireless communication unit 132 receives presence informationindicating that the mobile communication terminal 2 which is registeredin the presence monitoring target information is in an online state(step A15).

The mobile communication terminal 1 analyzes received presenceinformation (step A16). As a result of the analysis, the mobilecommunication terminal 1 recognizes that the mobile communicationterminal 2 which communicates via the second wireless communicationsystem 4, as in the second wireless communication unit 132, is in anonline state. The mobile communication terminal 1 consequently executesprocesses found in steps A17 and A18 both of which are utilized forturning the power of the second wireless communication unit 132 into anOFF state.

First of all, the mobile communication terminal 1 requests the callmanager server 5 to forward a reception, in order to cause the mobilecommunication terminal 2 being in an online state to receive datatransmitted from other electronic apparatuses to the second wirelesscommunication unit 132 (step A17). At the moment, the mobilecommunication terminal 1 may request to forward a reception with the useof one of the first wireless communication unit 131 and the secondwireless communication unit 132.

The call manager server 5 requests the number comparing DB server 8 toset forwarding of reception, in accordance with a request from themobile communication terminal 1 (step A58). The number comparing DBserver 8 receives a request to set forwarding of reception (step A80),and sets forwarding of reception (step A81). The call manager server 5refers to set information with the number comparing DB server 8, whenexecuting forwarding of reception.

Once a forwarding control unit 112 d provided at the mobilecommunication terminal 1 requests the call manager server 5 to forward areception, the electric power supply controlling unit 112 terminateselectric power supply into the second wireless communication unit 132(step A18).

This causes the second wireless communication unit 132 to be in a powerOFF state, until electric power is subsequently supplied.

The details concerning processes found in steps A16 to A18 are to behereinafter explained with reference to the flowchart found in FIG. 6.

In case of a transmitting electronic apparatus having a function to callsuccessively after confirmation regarding a presence PR of a receivingelectronic apparatus, a transmitting user is required to call bychoosing an electronic apparatus being in an online state among providedelectronic apparatuses by a communication partner. Therefore, processesfound in steps A17, A58, A80, and A81 which are employed for forwardingof reception need not necessarily to be performed. Furthermore, in sucha case, the mobile communication terminal 1 may not be provided with aforwarding information storage region 125 and a forwarding control unit112 d.

However, in case of a mobile communication terminal 1 including aforwarding information storage region 125 and a forwarding control unit112 d, a reception is forwarded to other electronic apparatuses eventhough a communicating electronic apparatus is in an offline state.Accordingly, a transmitting user may call without adverting to apresence PR found in a communicating electronic apparatus.

Next, the details concerning an operation of each constituent elementprovided at the presence communication system PS, when the mobilecommunication terminal 1 controls the state of the second wirelesscommunication unit 132 from “OFF” to “ON”, are to be explained, withreference to the flowcharts found in FIGS. 5A to 5C.

However, an operation state concerning the mobile communication terminal1 and the mobile communication terminal 2 when initiating processesillustrated in the flowcharts found in FIGS. 5A to 5C is assumed to be astate which has completed processes illustrated in the flowcharts foundin FIGS. 4A to 4C. In other words, the first wireless communication unit131 is supplied with electric power while electric power supply into thesecond wireless communication unit 132 is being terminated.

Furthermore, the mobile communication terminal 2 is in an idle statebecause the power of the mobile communication terminal 2 is turned toON.

In this state, when a user performs a power OFF operation provided forthe mobile communication terminal 2 (step B20 found in FIG. 5A),processes illustrated in the flowcharts found in FIGS. 5A to 5C areinitiated.

When a user performs a power OFF operation, the mobile communicationterminal 2 transmits a request to close a session to the call managerserver 5, via the second base station 4 a (step B21). The call managerserver 5 receives a request to close a session (step B50), and executesa process to close a session (step B51). This allows a session beingestablished in between the mobile communication terminal 2 and the callmanager server 5, to be closed (step B22). When the session is closed,the mobile communication terminal 2 turns the power to OFF (step B23),and awaits until the subsequent process is requested. Specifically, themobile communication terminal 2 terminates electric power supply into awireless communication unit, and awaits until a power ON operation isperformed.

Furthermore, the mobile communication terminal 2 requests the locationregistration server 6 to delete the registration of location informationvia the call manager server 5 when a request to close a session istransmitted, and requests the presence server 7 to modify presenceinformation. In order to perform this process, the call manager server 5requests the location registration server 6 to delete a registration oflocation information concerning the mobile communication terminal 2(step B52), and requests the presence server 7 to modify presenceinformation concerning the mobile communication terminal 2 (step B53).

The location registration server 6 receives a request to delete theregistration of location information (step B60), and executes a processto delete the registration of location information (step B61). Thepresence server 7 receives a request to modify presence information(step B70), and executes a process to modify the presence information(step B71). This allows the presence server 7 to recognize that themobile communication terminal 2 is transited into an offline state.

The presence server 7 notifies the first wireless communication unit 131provided at the mobile communication apparatus 1 of presence informationindicating that the mobile communication terminal 2 is transited into anoffline state, via the call manager server 5 and the first wirelesscommunication system 3 (step B72 found in FIG. 5B).

The first wireless communication unit 131 is notified of presenceinformation because the presence server 7 receives a request to registerpresence information concerning the first wireless communication unit131 provided at the mobile communication terminal 1 from the callmanager server 5 when establishing a session in between the firstwireless communication unit 131 and the call manager server 5, andrecognizes that the first wireless communication unit 131 provided atthe mobile communication apparatus 1 is in an online (valid) state.

Here, when the first wireless communication unit 131 being notified ofpresence information is in a discontinuous idle state which indicatesthat a traffic channel is disconnected in an idle state, the presenceinformation notifying apparatus 3 b may, for example, utilize an SMS(Short Message Service) or the like when notifying that the presenceinformation is in existence.

The first wireless communication unit 131 provided at the mobilecommunication terminal 1 receives presence information indicating thatthe mobile communication terminal 2, which is registered in the presencemonitoring target information, is in an offline state (step B10).

The mobile communication terminal 1 analyzes the received presenceinformation (step B11). As a result of the analysis, the mobilecommunication terminal 1 recognizes that the mobile communicationterminal 2 which communicates via the second wireless communicationsystem 4, as in the second wireless communication unit 132, is in anoffline state. The mobile communication terminal 1 consequently causes acommunication function provided for the second wireless communicationunit 132 to operate, thereby, supplying electric power into the secondwireless communication unit 132 (step B12).

Furthermore, the details concerning processes found in steps B11 and B12are to be hereinafter explained with reference to the flowchart found inFIG. 6.

The second wireless communication unit 132 transmits a request toestablish a session to the call manager server 5 via the second basestation 4 a (step B13). The call manager server 5 receives a request toestablish a session (step B54), and executes a process to establish asession (step B55). This allows a session to be established in betweenthe second wireless communication unit 132 and the call manager server 5(step B14).

Furthermore, the second wireless communication unit 132 requests thelocation registration server 6 to register location information via thecall manager server 5 when a request to establish a session istransmitted, and requests the presence server 7 to register presenceinformation. In order to perform this process, the call manager server 5requests the location registration server 6 to register locationinformation concerning the second wireless communication unit 132 (stepB56), and requests the presence server 7 to register presenceinformation concerning the second wireless communication unit 132 (stepB57).

The location registration server 6 receives a request to registerlocation information (step B62), and executes a process to registerlocation information concerning the second wireless communication unit132 provided at the mobile communication terminal 1 (step B63).

The presence server 7 recognizes that the second wireless communicationunit 132 provided at the mobile communication terminal 1 is in an online(valid) state, by a request from the call manager server 5 in step B57.The presence server 7 receives a request to register presenceinformation (step B73), and executes a process to register presenceinformation concerning the second wireless communication unit 132provided at the mobile communication terminal 1 (step B74).

The mobile communication terminal 1 requests the call manager server 5to deactivate forwarding of reception which is set at the numbercomparing DB server 8 and indicates that a reception addressed to thesecond wireless communication unit 132 is forwarded to the mobilecommunication terminal 2 (step B15 found in FIG. 5C). The call managerserver 5 requests the number comparing DB server 8 to deactivate thesetting of forwarding of reception (step B58).

The number comparing DB server 8 receives a request to deactivate thesetting of forwarding of reception (step B80), and deactivates thesetting of forwarding of reception (step B81).

In this way, the mobile communication terminal 1 causes the secondwireless communication unit 132, which is normally to receive areception, to operate when the power of the mobile communicationterminal 2, which receives data addressed to the second wirelesscommunication unit 132, is turned to OFF while the second wirelesscommunication unit 132 is in an power OFF state, and the settingemployed for forwarding of reception, which adopts the mobilecommunication terminal 2 as a forwarding destination, is deactivated.

The second wireless communication unit 132 is transited into an idlestate once requesting to deactivate forwarding of reception (step B16),and awaits until the subsequent process is requested.

Furthermore, the details concerning processes described in steps B11,B12, and B15, all of which illustrated in the flowcharts found in FIGS.5A to 5C, is to be explained with reference to the flowchart found inFIG. 6. The flowchart found in FIG. 6 not only includes processesdescribed in steps B11, B12, and B15, all of which are found in figures5A to 5C, but includes processes described in steps A16 to A18, all ofwhich are found in FIGS. 4A to 4C as well.

Furthermore, the mobile communication terminal 2 is picked up, in FIGS.4A to 4C and in FIGS. 5A to 5C, to exemplify the monitoring electronicapparatus for controlling electric power supply into the second wirelesscommunication unit 132. However, the monitoring electronic apparatusneeds only to be an electronic apparatus which is communicable via thesecond wireless communication system 4 being listed as the presencemonitoring target information as an example in FIG. 3. Furthermore, incase of a plurality of electronic apparatuses concurrently beingmonitored, turning any one of electronic apparatuses as monitoringtargets into an online state results in terminating electric powersupply into the second wireless communication unit 132 as beingillustrated in FIGS. 5A to 5C. Furthermore, turning all of theelectronic apparatuses as monitoring targets into an offline stateresults in supplying electric power into the second wirelesscommunication unit 132 as being illustrated in FIGS. 5A to 5C.

The electric power supply controlling process illustrated in theflowchart found in FIG. 6 is initiated by receiving presence informationfrom the presence server 7, via the first wireless communication system3 or via the second wireless communication system 4, by the firstwireless communication unit 131 or by the second wireless communicationunit 132 each of which provided at the mobile communication terminal 1.

In other words, the electric power supply controlling process isinitiated when the mobile communication terminal 1 receives presenceinformation in step A15 illustrated in FIG. 4C or in step B10illustrated in FIG. 5B. The processes described in steps C10 to C18 tobe hereinafter illustrated in FIG. 6 also correspond to processesdescribed in step A16 illustrated in FIG. 4C and in step B11 illustratedin FIG. 5B.

When one of the first wireless communication unit 131 and the secondwireless communication unit 132 receives presence information, thepresence information acquisition controlling unit 112 a acquires thereceived presence information from one of the first wirelesscommunication unit 131 and the second wireless communication unit 132(step C10), and records the acquired presence information in thepresence information storage region 121 (step C11).

The presence information acquisition controlling unit 112 a subsequentlynotifies the presence specifying unit 112 b of acquiring the presenceinformation (step C12).

The presence specifying unit 112 b determines as to whether presenceinformation of a monitoring target is stored in the presence informationstorage region 121, with reference to the presence monitoring targetinformation stored in the presence monitoring target information storageregion 122 (step C13). For example, the presence specifying unit 112 bdetermines as to whether an apparatus identifier AI provided for amonitoring target (alternate electronic apparatus) indicated by thepresence monitoring target information illustrated in FIG. 3B isincluded within an apparatus identifier AI stored in the presenceinformation storage region 121. If no presence information of amonitoring target is stored in the presence information storage region121 (step C13; No), the controlling unit 11 terminates the electricpower supply controlling process and awaits until the subsequentpresence information is received.

If presence information of a monitoring target is stored in the presenceinformation storage region 121 (step C13; Yes), the electric powersupply determining unit 112 c determines as to whether the secondwireless communication unit 132 is supplied with electric power, withreference to the electric power supply state storage region 123 (stepC14).

When the second wireless communication unit 132 is supplied withelectric power and the second wireless communication unit 132 is in anoperation (step C14; Yes), the electric power supply determining unit112 c determines as to whether a monitoring target in an online state isin existence, with reference to presence information of the monitoringtarget within the presence information storage region 121 (step C15).For example, the electric power supply determining unit 112 c determinesas to whether even one monitoring target whose presence PR is “online”is in existence, when presence information of a plurality of monitoringtargets is included in the presence information storage region 121.

If no monitoring target in an online state is found (step C15; No), thecontrolling unit 11 terminates the electric power supply controllingprocess, and awaits until the subsequent presence information isreceived.

If even one monitoring target in an online state is found (step C15;Yes), the electric power supply determining unit 112 c furtherdetermines as to whether communication state of the second wirelesscommunication unit 132 is “connect state”, with reference to thecommunication state storage region 124 (step C16).

When the second wireless communication unit 132 is in connect state(step C16; Yes), the electric power supply determining unit 112 cdetermines as to whether one of the first wireless communication unit131 and the second wireless communication unit 132 received furtherpresence information (step C17).

If the further presence information is not received (step C17; No), thecontrolling unit 11 moves a process to step C16, and the electric powersupply determining unit 112 c waits until communication state of thesecond wireless communication unit 132 is turned into a non connectstate. If the further presence information is received (step C17; Yes),the controlling unit 11 moves a process to step C10, and the electricpower supply controlling unit 112 initiates the electric power supplycontrolling process from the start based on the further presenceinformation.

When the second wireless communication unit 132 is not in connect state(step C16; No), the forwarding control unit 112 d requests the callmanager server 5 to forward a reception, in order to forward, to amonitoring target in an online state, data transmitted to the secondwireless communication unit 132 from other electronic apparatuses (stepA17). For example, when a plurality of monitoring targets in an onlinestate are in existence, the forwarding control unit 112 d requests thecall manager server 5 to forward a reception, in order to forward areception to any one of the targets.

Once the forwarding control unit 112 d requests the call manager server5 to forward a reception, the electric power supply determining unit 112c terminates electric power supply into the second wirelesscommunication unit 132 (step A18). This allows the second wirelesscommunication unit 132 to be in a power OFF state, until subsequentlybeing supplied with electric power and being activated.

On the other hand, even though it is determined that the second wirelesscommunication unit 132 is not supplied with electric power and thesecond wireless communication unit 132 is not in an operation in stepC14 (step C14; No), the electric power supply determining unit 112 cdetermines as to whether a monitoring target in an online state is inexistence, with reference to the presence information of the monitoringtarget within the presence information storage region 121 (step C18) asin step C15.

If even one monitoring target in an online state is found (step C18;Yes), the second wireless communication unit 132 needs not to beoperated. Therefore, the controlling unit 11 terminates the electricpower supply controlling process, and awaits until the subsequentpresence information is received.

If no monitoring target in an online state is found (step C18; No), amonitoring target does not receive data forwarded from the secondwireless communication unit 132. Therefore, the second wirelesscommunication unit 132 needs to be operated so as to be received at thesecond wireless communication unit 132.

At the moment, the electric power supply determining unit 112 c outputsan instruction signal which instructs the power source controller 15 ato supply electric power into the second wireless communication unit132, thereby, initiating electric power supply into the second wirelesscommunication unit 132. The power source controller 15 a receives aninstruction signal, and supplies electric power into the second wirelesscommunication unit 132 with controlling the battery 15 b (step B12).

The forwarding control unit 112 d requests the call manager server 5 todeactivate forwarding of reception which is set in the number comparingDB server 8 and indicates that a reception addressed to the secondwireless communication unit 132 is forwarded to the mobile communicationterminal 2 (step B15).

The mobile communication terminal 1 awaits until the subsequent presenceinformation is received.

Here, whether or not a reception state of the wireless signal by thefirst wireless communication unit 131 is favorable may further bedetermined in step C16. In case that a reception state of the firstwireless communication unit 131 is unfavorable, a reception of presenceinformation by the first wireless communication unit 131 cannot be done,after the second wireless communication unit 132 is transited into apower OFF state. In this case, when a communication state of the firstwireless communication unit 131 is determined to be unfavorable, theelectric power supply determining unit 112 c only needs not to terminateelectric power supply into the second wireless communication unit 132,until a communication state of the first wireless communication unit 131is turned to be favorable.

Furthermore, when executing a process described in step C16, even thougha reception state of the wireless signal by the first wirelesscommunication unit 131 is favorable, a reception state of the wirelesssignal by the first wireless communication unit 131 may be turned to beunfavorable after the second wireless communication unit 132 istransited into a power OFF state. In order to solve this problem, when acommunication state of the first wireless communication unit 131 isdetermined to be unfavorable, electric power supply into the secondwireless communication unit 132 only needs to be immediately initiated.This allows the first wireless communication unit 131 and the secondwireless communication unit 132 to avoid concurrently being in a statewhich unables reception of a wireless signal.

Furthermore, when the second wireless communication unit 132 is in apower OFF state, electric power supply into the second wirelesscommunication unit 132 may be allowed to immediately be restarted when auser is in an attempt to communicate with the use of the second wirelesscommunication unit 132.

At the moment, in order to detect initiation of communication with theuse of the second wireless communication unit 132, for example, it isonly required to detect an execution command concerning communicationwith the use of the second wireless communication unit 132 by a userfrom the operation unit 16 being input. Specifically, the operation unit16 accepts an input of an instruction information for initiatingcommunication by the second wireless communication unit 132, in responseto an operation of a user. The electric power supply controlling unit112 restarts electric power supply into the second wirelesscommunication unit 132, when the instruction information is inputthrough the operation unit 16 after electric power supply into thesecond wireless communication unit 132 is terminated. Furthermore, inorder to detect initiation of communication with the use of the secondwireless communication unit 132, the storing unit 12 may be required tobe store an application in association with the second wirelesscommunication unit 132 and activation of the application by the user maybe detected. This allows the user to communicate with the use of thesecond wireless communication unit 132, when being desired.

As being explained above, the mobile communication terminal 1 accordingto embodiment 1 is comprised of the first wireless communication unit131 which communicates via the first wireless communication system 3 andthe second wireless communication unit 132 which communicates via thesecond wireless communication system 4. The mobile communicationterminal 1 adopts an electronic apparatus (alternate, electronicapparatus) communicating via the second wireless communication system 4,in place of the second wireless communication unit 132, as a monitoringtarget. The presence information acquisition controlling unit 112 aacquires presence information indicating a communication state of amonitoring target from the presence server 7. The electric power supplydetermining unit 112 c determines as to whether the monitoring target isin a communicable online state, based on the acquired presenceinformation. The electric power supply determining unit 112 c suppresseselectric power to be consumed by the second wireless communication unit132, once the monitoring target is determined to be in an online state.

According to the mobile communication terminal 1 in embodiment 1, whenthe electronic apparatus being as a monitoring target is in an onlinestate, the electronic apparatus is communicable in place of the secondwireless communication unit 132. Accordingly, it is possible to suppresselectric power to be consumed by the second wireless communication unit132. Therefore, according to embodiment 1, it is possible to suppresselectric power consumption of the mobile communication terminal 1 as awhole.

Furthermore, according to embodiment 1, when electric power consumed bythe second wireless communication unit 132 is not suppressed, thepresence information acquisition controlling unit 112 a acquirespresence information from the presence server 7 via any one of the firstwireless communication system 3 and the second wireless communicationsystem 4. On the other hand, when electric power consumed by the secondwireless communication unit 132 is suppressed, the presence informationacquisition controlling unit 112 a acquires presence information fromthe presence server 7 via the first wireless communication system 3.Further, the electric power supply determining unit 112 c deactivatessuppressing electric power consumed by the second wireless communicationunit 132, once the presence information acquisition controlling unit 112a acquires presence information indicating that the monitoring target isnot in an online state while suppressing electric power consumed by thesecond wireless communication unit 132.

Accordingly, according to the mobile communication terminal 1 inembodiment 1, when a monitoring target is transited into aincommunicable state, electric power is consumed again by the secondwireless communication unit 132, therefore, electric power consumptionmay be suppressed with having at least one of the monitoring target andthe second wireless communication unit 132 being in a communicablestate.

Furthermore, according to embodiment 1, the presence monitoring targetinformation storage region 122 stores presence monitoring targetinformation indicating an apparatus identifier AI being as a monitoringtarget. The presence information acquisition controlling unit 112 aacquires an apparatus identifier AI for use in identifying an electronicapparatus on a communication network and a presence PR of an electronicapparatus being specified by the apparatus identifier in associationwith one another from the presence server 7, via any one of the firstwireless communication system 3 and the second wireless communicationsystem 4. The presence specifying unit 112 b determines as to whetherthe apparatus identifier AI acquired by the presence informationacquisition controlling unit 112 a is stored in the presence monitoringtarget information storage region 122. The presence PR being inassociation with the apparatus identifier AI which is determined to bestored in the presence monitoring target information storage region 122by the presence specifying unit 112 b is adopted as presence informationof a monitoring target.

Accordingly, according to the mobile communication terminal 1 inembodiment 1, presence information of a monitoring target canappropriately be acquired.

Furthermore, according to embodiment 1, the electric power supplydetermining unit 112 c executes electric power supply into the secondwireless communication unit 132, when a monitoring target is not in anonline state. The electric power supply determining unit 112 c alsoterminates electric power supply into the second wireless communicationunit 132, when a monitoring target is in an online state.

Accordingly, according to the mobile communication terminal 1 inembodiment 1, electric power consumption by the mobile communicationterminal 1 can be suppressed by controlling electric power supply intothe second wireless communication unit 132.

Furthermore, according to embodiment 1, the first wireless communicationunit 131 represents a wide-area wireless communication unit whichcommunicates via a base station of the first wireless communicationsystem 3 being as a wide-area wireless communication network. The secondwireless communication unit 132 represents a local wirelesscommunication unit which communicates via a base station of the secondwireless communication system 4 being as a local wireless communicationnetwork. The local wireless communication network has a base stationwith a more restricted reachable area of an electric wave than a basestation of the wide-area wireless communication network.

Accordingly, according to the mobile communication terminal 1 inembodiment 1, electric power consumed by the local wirelesscommunication unit can be suppressed.

Furthermore, according to embodiment 1, when the electric power supplydetermining unit 112 c determines that a monitoring target is in anonline state, the forwarding control unit 112 d transmits a request toforward a reception, to the number comparing DB server 8 being as aforwarding server via the call manager server 5. The request is toforward information to be transmitted to the second wirelesscommunication unit 132 via the second wireless communication system 4,to the monitoring target.

Accordingly, according to embodiment 1, forwarding is automaticallyexecuted by the call manager server 5 which refers to the numbercomparing DB server 8. Therefore, the transmitter can communicatewithout searching for an electronic apparatus which communicates inplace of the second wireless communication unit 132.

Embodiment 2

Next, an explanation according to embodiment 2 of the present inventionis to be given with reference to FIGS. 1, 7, and 8.

Embodiment 2 exemplifies reduction of dissipating electric power storedin the battery 15 b for use in being supplied into the first wirelesscommunication unit 131 and into the second wireless communication unit132 for use in an operation, with modifying a discontinuous receptioncycle indicating a cycle of a timing at which a communication functionprovided for a wireless communication unit operates in idle state.Further, in FIGS. 7 and 8, the equivalent reference numeral is given fora constituent element which is equivalent to the constituent elementindicated in FIGS. 2 and 6.

First of all, an explanation concerning the circuit configurationregarding the mobile communication terminal 1 according to embodiment 2is to be given with reference to FIG. 7.

The controlling unit 11 described by embodiment 2 is provided with adiscontinuous reception cycle determining unit 112 e and a timer unit113.

The discontinuous reception cycle determining unit 112 e sets adiscontinuous reception cycle indicating a cycle in which communicationfunctions provided at the first wireless communication unit 131 and thesecond wireless communication unit 132 intermittently operate, withreference to the results determined by the presence specifying unit 112b, discontinuous reception cycle information stored in the storing unit12, and a communication state concerning the communication unit 13within the communication state storage region 124. Furthermore, thediscontinuous reception cycle determining unit 112 e causes thediscontinuous reception cycle storage region 126 to store the setdiscontinuous reception cycle.

Here, an discontinuous reception cycle represents a predetermined timecycle which indicates a cycle of a timing at which electric power issupplied into the first wireless communication unit 131 and into thesecond wireless communication unit 132 from the battery 15 b in order tooperate communication functions provided at the first wirelesscommunication unit 131 and at the second wireless communication unit132.

A discontinuous reception cycle is set so as to synchronize a time slotTS defined by wireless signals received by the first wirelesscommunication unit 131 and by the second wireless communication unit 132in an idle state. The wireless signals include information to bereceived for each time cycle of the time slot TS.

The timer unit 113 detects that an elapsed time reached thediscontinuous reception cycle by timing the elapsed time from thecompletion time concerning an immediately preceding reception processbeing performed.

The discontinuous reception cycle storage region 126 described byembodiment 2 stores a normal discontinuous reception cycle T1 and apredetermined electric power saving discontinuous reception cycle T2which is set so as to having a larger value than the normaldiscontinuous reception cycle T1.

Furthermore, the discontinuous reception cycle storage region 126 storesa first reception cycle flag F1 which indicates as to which one of thenormal discontinuous reception cycle T1 and the electric power savingdiscontinuous reception cycle T2 is presently employed as the basis ofan operation caused by the first wireless communication unit 131, and asecond reception cycle flag F2 which indicates as to which one of thenormal discontinuous reception cycle T1 and the electric power savingdiscontinuous reception cycle T2 is presently employed as the basis ofan operation caused by the second wireless communication unit 132.

The communication controlling unit 111 controls communication caused bythe first wireless communication unit 131 and by the second wirelesscommunication unit 132, with reference to the first reception cycle flagF1 and to the second reception cycle flag F2, based on the discontinuousreception cycles indicated by the first reception cycle flag F1 and bythe second reception cycle flag F2.

Furthermore, the power source controller 15 a continues/terminateselectric power supply into the first wireless communication unit 131 andinto the second wireless communication unit 132, based on thediscontinuous reception cycle stored in the discontinuous receptioncycle storage region 126.

Next, an explanation concerning a discontinuous reception cyclecontrolling process in which electric power supply controlling unit 112,illustrated in FIG. 7, controls a discontinuous reception cycle of thesecond wireless communication unit 132 based on presence informationreceived by the mobile communication terminal 1 is given with referenceto the flowchart found in FIG. 8.

The discontinuous reception cycle controlling process described in theflowchart illustrated in FIG. 8 is initiated by receiving presenceinformation from the presence server 7, via one of the first wirelesscommunication system 3 and the second wireless communication system 4,by one of the first wireless communication unit 131 and the secondwireless communication unit 132 each of which provided at the mobilecommunication terminal 1.

When one of the first wireless communication unit 131 and the secondwireless communication unit 132 receives the presence information, thepresence information acquisition controlling unit 112 a acquires thereceived presence information from one of the first wirelesscommunication unit 131 and the second wireless communication unit 132(step C10), and records the acquired presence information in thepresence information storage region 121 (step C11).

The presence information acquisition controlling unit 112 a subsequentlynotifies the presence specifying unit 112 b of acquiring presenceinformation (step C12).

The presence specifying unit 112 b determines as to whether presenceinformation of a monitoring target is stored in the presence informationstorage region 121, with reference to the presence monitoring targetinformation stored in the presence monitoring target information storageregion 122 (step C13). If no presence information of a monitoring targetis stored in the presence information storage region 121 (step C13; No),the controlling unit 11 terminates the discontinuous reception cyclecontrolling process and awaits until the subsequent presence informationis received.

If presence information of a monitoring target is stored in the presenceinformation storage region 121 (step C13; Yes), the discontinuousreception cycle determining unit 112 e determines as to whether andiscontinuous reception cycle operating a communication functionprovided for the second wireless communication unit 132 represents anormal discontinuous reception cycle T1 or an electric power savingdiscontinuous reception cycle T2, with reference to a second receptioncycle flag F2 stored in the discontinuous reception cycle storage region126 (step D10).

When the second wireless communication unit 132 is being operated basedon the normal discontinuous reception cycle T1 (step D10; Yes), thediscontinuous reception cycle determining unit 112 e determines as towhether a monitoring target in an online state is in existence, withreference to presence information of the monitoring target within thepresence information storage region 121 (step C15).

If no monitoring target in an online state is found (step C15; No), thecontrolling unit 11 terminates the discontinuous reception cyclecontrolling process, and awaits until the subsequent presenceinformation is received.

If even one monitoring target in an online state is found (step C15;Yes), the discontinuous reception cycle determining unit 112 e furtherdetermines as to whether communication state of the second wirelesscommunication unit 132 is “connect state”, with reference to thecommunication state storage region 124 (step C16):

When the second wireless communication unit 132 is in connect state(step C16; Yes), the discontinuous reception cycle determining unit 112e determines as to whether one of the first wireless communication unit131 and the second wireless communication unit 132 received furtherpresence information (step C17).

If the further presence information is not received (step C17; No), thecontrolling unit 11 moves the process to step C16, and the discontinuousreception cycle determining unit 112 e waits until communication stateof the second wireless communication unit 132 is turned into a nonconnect state. If the further presence information is received (stepC17; Yes), the controlling unit 11 moves the process to step C10, andthe electric power supply controlling unit 112 initiates thediscontinuous reception cycle controlling process from the start, basedon the further presence information.

When the second wireless communication unit 132 is not in connect state(step C16; No), the forwarding control unit 112 d requests the callmanager server 5 to forward a reception, in order to forward, to amonitoring target in an online state, data transmitted to the secondwireless communication unit 132 from other electronic apparatuses (stepA17).

Once the forwarding control unit 112 d requests the call manager server5 to forward a reception, in order to lengthen the discontinuousreception cycle for communication by the second wireless communicationunit 132, the discontinuous reception cycle determining unit 112 emodifies (rewrites) the contents indicated by the second reception cycleflag F2 to the electric power saving discontinuous reception cycle T2(step D11). The communication controlling unit 111 operates the secondwireless communication unit 132 in the electric power savingdiscontinuous reception cycle T2, with reference to the modified secondreception cycle flag F2.

On the other hand, even though it is determined that the second wirelesscommunication unit 132 being operated based on the electric power savingdiscontinuous reception cycle T2 in step D10 (step D10; No), thediscontinuous reception cycle determining unit 112 e determines as towhether a monitoring target in an online state is in existence, withreference to the presence information of the monitoring target withinthe presence information storage region 121 (step C18), as in step C15.

If even one monitoring target in an online state is found (step C18;Yes), the controlling unit 11 terminates the discontinuous receptioncycle controlling process in consideration of lacking necessity whichrequires the second wireless communication unit 132 to be operated inthe normal discontinuous reception cycle T1, and awaits until thesubsequent presence information is received.

If no monitoring target in an online state is found (step C18; No), amonitoring target does not receive data forwarded from the secondwireless communication unit 132. Therefore, the discontinuous receptioncycle determining unit 112 e operates the second wireless communicationunit 132 based on the normal discontinuous reception cycle T1 in orderto ensure reception by the second wireless communication unit 132.

In order to shorten a discontinuous reception cycle for communication bythe second wireless communication unit 132, therefore, the discontinuousreception cycle determining unit 112 e modifies (rewrites) the contentsindicated by the second reception cycle flag F2 to the normaldiscontinuous reception cycle T1 (step D12). The communicationcontrolling unit 111 operates the second wireless communication unit 132in the normal discontinuous reception cycle T1, with reference to themodified second reception cycle flag F2.

The forwarding control unit 112 d requests the call manager server 5 todeactivate forwarding of reception which is set in the number comparingDB server 8 and indicates that a reception addressed to the secondwireless communication unit 132 is forwarded to the mobile communicationterminal 2 (step B15).

The mobile communication terminal 1 awaits unit the subsequent presenceinformation is received.

As being described above, when the monitoring target is not in an onlinestate, the discontinuous reception cycle determining unit 112 e providedat the mobile communication terminal 1 according to embodiment 2 sets andiscontinuous reception cycle of the second wireless communication unit132 to a normal discontinuous reception cycle T1 being as a standardcycle. Furthermore, when the monitoring target is in an online state,the discontinuous reception cycle determining unit 112 e sets adiscontinuous reception cycle of the second wireless communication unit132 to an electric power saving discontinuous reception cycle T2 havinga cycle being longer than the standard cycle. When the second wirelesscommunication unit 132 is being operated in an electric power savingdiscontinuous reception cycle T2, consumed electric power is reducedcompared with an operation in the normal discontinuous reception cycleT1.

Accordingly, according to the mobile communication terminal 1 inembodiment 2, electric power consumption by the mobile communicationterminal 1 can be suppressed by controlling the discontinuous receptioncycle of the second wireless communication unit 132.

Furthermore, while embodiment 2 assumes a predetermined fixed value as anormal discontinuous reception cycle T1 and an electric power savingdiscontinuous reception cycle T2, a user may change the values. In thiscase, a user may increase a value of the electric power savingdiscontinuous reception cycle T2 when further desiring reduction ofelectric power consumption.

Furthermore, when both timeliness and speed of communication, ratherthan electric power dissipation of the battery 15 b, are prioritized, avalue of the electric power saving discontinuous reception cycle T2 maybe decreased.

In this case, the operation unit 16 accepts an input of modificationinformation for modifying the electric power saving discontinuousreception cycle T2, in response to an operation of a user. Based on themodification information concerning the electric power savingdiscontinuous reception cycle T2 input through the operation unit 16, bya user's operation, the controlling unit 11 modifies a value of theelectric power saving discontinuous reception cycle T2 stored in thediscontinuous reception cycle storage region 126. The discontinuousreception cycle determining unit 112 e executes a discontinuousreception cycle controlling process illustrated in FIG. 8; with the useof the modified electric power saving discontinuous reception cycle T2stored in the discontinuous reception cycle storage region 126.

Furthermore, while embodiment 2 assumes the second wirelesscommunication unit 132 as a target which modifies a discontinuousreception cycle in order to reduce electric power consumption, awireless communication unit which modifies a discontinuous receptioncycle may be changeable by the operation of the operation unit 16 by auser. In this case, in order to reduce electric power consumption, themobile communication terminal 1 controls a discontinuous reception cycleof the wireless communication unit chosen by the user among a pluralityof wireless communication units. Specifically, the operation unit 16accepts an input of chosen information for specifying the first wirelesscommunication unit 131 or the second wireless communication unit 132, inresponse to an operation of a user. The electric power supplycontrolling unit 112 suppresses electric power to be consumed by thewireless communication unit specified by the chosen information beinginput through the operation unit 16.

This allows a user to choose a wireless communication unit whichmodifies a discontinuous reception cycle, depending on utilizationstatus, utilization frequency, and others, of the wireless communicationunit.

Furthermore, an option may be given in such a way that a user may decideas to whether an operation for use in reducing electric powerconsumption provided for the wireless communication unit is to beexecuted. In this case, the operation unit 16 accepts an input ofinstruction information for initiating communication by the secondwireless communication unit 132, in response to an operation of a user.When a discontinuous reception cycle of the second wirelesscommunication unit 132 is set in an electric power saving discontinuousreception cycle T2, the discontinuous reception cycle of the secondwireless communication unit 132 is reset to a normal discontinuousreception cycle T1 once the instruction to initiate communication by thesecond wireless communication unit 132 is input in the operation unit 16by a user's operation.

This allows assuredness of communication to be prioritized, whendesiring to secure as much assuredness of communication as possible evenin case of low electric power remaining in a battery.

The first wireless communication system 3 according to the embodiment ofthe present invention may employ a portable communication system with acellular method such as a GSM (Global System Mobile Communications). Thesecond wireless communication system 4 may also employ a local wirelesscommunication system such as a UWB (Ultra Wide Band) by way of example.

According to a presence communication system PS in accordance with theembodiment of the present invention, for example, when a user having themobile communication terminal 1 performs data communication with the useof the notebook personal computer in an outside location, electric powersupply into the second wireless communication unit 132 can beterminated, by receiving data by the notebook personal computer in placeof the second wireless communication unit 132 provided at the mobilecommunication terminal 1.

Furthermore, an electronic apparatus corresponding to an apparatusidentifier AI registered in the presence monitoring target informationneeds only to be a communicable electronic apparatus with the use ofdata, and may also be an electronic wrist watch, a white good, anaudio-visual equipment, and others, having a communication function,other than a PC, a PDA, a car navigation apparatus, and a televisionapparatus as being exemplified in FIG. 3B.

Furthermore, the mobile communication terminal 1 according to theabove-mentioned embodiment can be achieved with the use of a computerhaving a plurality of communication units.

For example, an explanation concerning the mobile communication terminal1 according to the above-mentioned embodiment is given with anassumption utilizing a predetermined operation program stored in thestoring unit 12. However, an apparatus executing the above-mentionedprocess may be constituted by distributing a program executing theabove-mentioned process operation being stored in computer-readablerecording medium such as a flexible disk, a CD-ROM (Compact DiskRead-Only Memory), a DVD (Digital Versatile Disk), and an MO(Magneto-Optical disk) and by installing the program at a computer.

Furthermore, a program may be stored in a disk apparatus and othersincluded in a predetermined server apparatus on a communication networksuch as the Internet, and may be allowed to be downloaded into acomputer by superimposing on a carrier wave by way of example.Furthermore, the above-mentioned process can be achieved byactivating/executing a program while being forwarded via a communicationnetwork.

Furthermore, in case of achieving the above-mentioned function withassigning tasks to OSs (Operating System) or in case of achieving withcooperating with OSs and applications, and in other cases, only portionsother than OSs may be stored in medium to be distributed, and may bedownloaded in a computer or the like.

Various embodiments and changes may be made thereunto without departingfrom the broad spirit and scope of the invention. The above-describedembodiments are intended to illustrate the present invention, not tolimit the scope of the present invention. The scope of the presentinvention is shown by the attached claims rather than the embodiments.Various modifications made within the meaning of an equivalent of theclaims of the invention and within the claims are to be regarded to bein the scope of the present invention.

This application is based on Japanese Patent Applications No.2006-315481 filed on Nov. 22, 2006 and No. 2007-299802 filed on Nov. 19,2007, and including specification, claims, drawings and summary. Thedisclosures of the above Japanese Patent Applications are incorporatedherein by reference in their entireties.

What is claimed is:
 1. An electronic apparatus which communicates via aplurality of communication networks including a first communicationnetwork and a second communication network being different from thefirst communication network, comprising: a plurality of communicationunits including a first communication unit which communicates via thefirst communication network and a second communication unit whichcommunicates via the second communication network; a presenceinformation acquiring unit which acquires presence informationindicating a communication state of an alternate communication apparatusbeing as a communication apparatus which communicates via the secondcommunication network in place of the second communication unit; anonline determining unit which determines as to whether the alternatecommunication apparatus is in an online state, based on the presenceinformation acquired by the presence information acquiring unit; and aconsumed electric power controlling unit which suppresses electric powerto be consumed by the second communication unit, when the onlinedetermining unit determines that the alternate communication apparatusis in an online state.
 2. The electronic apparatus according to claim 1,wherein: the presence information acquiring unit acquires presenceinformation of the alternate communication apparatus via at least one ofplurality of the communication networks when the consumed electric powerof the second communication unit is not suppressed, and acquirespresence information of the alternate communication apparatus via atleast one of communication networks other than the second communicationnetwork among a plurality of the communication networks when theconsumed electric power of the second communication unit is suppressedby the consumed electric power controlling unit, and the consumedelectric power controlling unit deactivates suppression of consumedelectric power of the second communication unit, when the onlinedetermining unit determines that the alternate communication unit is notin an online state while suppressing consumed electric power of thesecond communication unit.
 3. The electronic apparatus according toclaim 1, further comprising an alternate apparatus identifier storingunit which stores an apparatus identifier of the alternate communicationapparatus, wherein the presence information acquiring unit includes: acommunication apparatus information acquiring unit which acquires anapparatus identifier for identifying a communication apparatus andpresence information of a communication apparatus specified by theapparatus identifier in association with one another, from a presenceserver managing a communication state of a communication apparatus on acommunication network, via at least one of plurality of thecommunication networks; an alternate determining unit which determinesas to whether an apparatus identifier acquired by the communicationapparatus information acquiring unit is stored in the alternateapparatus identifier storing unit; and an alternate communicationapparatus presence information acquiring unit which acquires, aspresence information of the alternate communication apparatus, presenceinformation acquired by the communication apparatus informationacquiring unit in association with an apparatus identifier which isstored in the alternate apparatus identifier storing unit, when thealternate determining unit determines that the apparatus identifier isstored in the alternate apparatus identifier storing unit.
 4. Theelectronic apparatus according to claim 1, wherein the consumed electricpower controlling unit includes an electric power supply controllingunit which executes electric power supply into the second communicationunit when the online determining unit determines that an alternatecommunication unit is not in an online state, and terminates electricpower supply into the second communication unit when the onlinedetermining unit determines that an alternate communication apparatus isin an online state.
 5. The electronic apparatus according to claim 4further comprising an operation unit which accepts an input of aninstruction information for initiating communication by the secondcommunication unit, in response to an operation of a user, wherein theelectric power supply controlling unit restarts electric power supplyinto the second communication unit, when instruction information isinput through the operation unit after electric power supply into thesecond communication unit is terminated.
 6. The electronic apparatusaccording to claim 1, wherein the consumed electric power controllingunit includes a discontinuous reception cycle controlling unit whichsets a discontinuous reception cycle of the second communication unit toa predetermined standard cycle when the online determining unitdetermines that an alternate communication apparatus is not in an onlinestate, and sets the discontinuous reception cycle to an electric powersaving cycle having a cycle being longer than the predetermined standardcycle when the online determining unit determines that an alternatecommunication apparatus is in an online state.
 7. The electronicapparatus according to claim 6, further comprising: a discontinuousreception cycle storing unit which stores the electric power savingcycle; an operation unit which accepts an input of modificationinformation for modifying the electric power saving cycle, in responseto an operation of a user; and a discontinuous reception cyclemodification unit which modifies an electric power saving cycle storedin the discontinuous reception cycle storing unit, based on themodification information being input through the operation unit, whereinthe discontinuous reception cycle controlling unit sets thediscontinuous reception cycle to the electric power saving cycle storedin the discontinuous reception cycle storing unit, when the onlinedetermining unit determines that an alternate communication apparatus isin an online state.
 8. The electronic apparatus according to claim 6,further comprising an operation unit which accepts an input ofinstruction information for initiating communication by the secondcommunication unit, in response to an operation of a user, wherein thediscontinuous reception cycle controlling unit resets the discontinuousreception cycle to the predetermined standard cycle, when instructioninformation is input through the operation unit after the discontinuousreception cycle is set to the electric power saving cycle.
 9. Theelectronic apparatus according to claim 1, wherein the firstcommunication network is a wide-area wireless communication network, thefirst communication unit is a wide-area wireless communication unitwhich communicates via a base station of the wide-area wirelesscommunication network, the second communication network is a localwireless communication network having a base station with a morerestricted reachable area of an electric wave than a base station of thewide-area wireless communication network, and the second communicationunit is a local wireless communication unit which communicates via abase station of the local wireless communication network.
 10. Theelectronic apparatus according to claim 1, further comprising aforwarding request unit which transmits a forwarding request, to aforwarding server connected to the second communication network, forforwarding information to be transmitted to the second communicationunit via the second communication network, to an alternate communicationapparatus which is in an online state, when the online determining unitdetermines that the alternate communication apparatus is in an onlinestate.
 11. The electronic apparatus according to claim 1, furthercomprising an operation unit which accepts an input of choseninformation for specifying one communication unit being chosen among aplurality of the communication units, in response to an operation of auser, wherein the consumed electric power controlling unit suppresseselectric power to be consumed by the communication unit specified by thechosen information being input through the operation unit.
 12. Apresence communication system, comprising: a presence server whichmanages a communication state of a communication apparatus; and anelectronic apparatus which communicates via a plurality of communicationnetworks including a first communication network and a secondcommunication network being different from the first communicationnetwork, wherein the presence server transmits presence informationindicating a communication state of an alternate communication apparatusbeing as a communication apparatus which communicates via the secondcommunication network in place of the second communication unit, to theelectronic apparatus, and the electronic apparatus, comprises: aplurality of communication units including a first communication unitwhich communicates via the first communication network and a secondcommunication unit which communicates via the second communicationnetwork; a presence information acquiring unit which acquires presenceinformation of the alternate communication apparatus transmitted by thepresence server, via at least one of a plurality of the communicationnetworks; an online determining unit which determines as to whether thealternate communication apparatus is in an online state, based on thepresence information acquired by the presence information acquiringunit; and a consumed electric power controlling unit which suppresseselectric power to be consumed by the second communication unit, when theonline determining unit determines that the alternate communicationapparatus is in an online state.
 13. A non-transitory computer-readablerecording medium storing a program which causes a computer, comprising aplurality of communication units including a first communication unitwhich communicates via a first communication network and a secondcommunication unit which communicates via a second communication networkbeing different from the first communication network, and communicatingvia a plurality of communication networks including the firstcommunication network and the second communication network, to execute:a presence information acquiring step of acquiring presence informationindicating a communication state of an alternate communication apparatusbeing as a communication apparatus which communicates via the secondcommunication network in place of the second communication unit; anonline determining step of determining as to whether the alternatecommunication apparatus is in an online state, based on the presenceinformation acquired in the presence information acquiring step; and aconsumed electric power controlling step which suppresses electric powerto be consumed by the second communication unit, when it is determinedthat the alternate communication apparatus is in an online state in theonline determining step.